Improvement in balance slide-valves



UNITED STATES PATENT QEETGE.

IMPROVEMENT IN BALANCE SLIDE-VALVES.

Specification forming part of Letters Patent No. 58,699., dated October 9, 1866.

To all whom it may concern:

Be it known that I, JOHN H. WAIT, of Ports- 1nouth,in the county of Scioto and State of Ohio, have invented a new and useful Improvement in Balance Slide-Valves; and I do hereby declare the following to be a Jfull, clear, and exact description of the same, reference being had to the accompanying drawings, which are made a part ot' this specification, and in which- Figure lis a vertica-l longitudinal section of a steam-cylinder with my improved valve applied. Fig. 2 is a horizontal section ot' the saine, the line o: x, Fig. 1, indicating the plane of section. Fig. 3 is a detail view, showing the inner face ot one of the valves in elevation.

Similar letters ot" reference indicate correspondin g parts in the several figures.

This invention relates to a slide-valve for regulating the supply and exhaustI of steam in a steam-cylinder, and consists in a valve-block mounted upon and communicating with the steam-chan nels on to'p of the cylinder, and provided on either side with a reciprocating valve having steam passages or channels, which are alternately brought into communication with the supply and exhaust ports of the valveblock.

In order that others skilled iu the art to which my invention appertains may be enabled to fully understand and use the same, I will proceed to describe it in connection with the accompanying drawings.

A represents the block or main body of the valve, which occupies a xed position midway between the ends of the cylinder B and com municates with the latter through the steamchannel O C. D Drepresentslide-valves workA ing at the opposite sides of the valve-block A, and reciprocated simultaneously in the same direction bythe valve-rod E.

F represents the steamsupply port, and G G the exhaust-ports. In Fig. 2 the dotted circles designate the position ot' these ports, and in this figure will also be more clearly seen the arrangement of said ports in relation to the steam-passages d ell d2 of valves D D and c al a2 a3 a4 ct' valve-block A.

The valves D D are connected together by the bolts H H and nuts I I, and are thereby held sufciently tight against the valve-block A to prevent the waste ot' steam. The bolts H H at the ends of the valve are provided with rollers J J, which traverse guidcways at b b, and serve to relieve the bearings of the valve from friction.

The operation of this valve may be briey stated, and will be readily understood.

The steam-channels O C alternately become thesupply and exhaust passages for the steamcylinder, for which purpose the passages al a? of the valve-block A are in constant communication with the steam-channels C C', the passages a a4 are in constant communication with the exhaust-ports G G, and the central passage, a2, ot' the valve-block A is always in communication with the supply-port F. Vhen C becomes the steam-supply channel and C the exhaust-channel the relation between the several passages in the valves D D, valveG block A, and steam and exhaust vports is as represented in Fig. 2that is to say, the central passages, d1 d1, of the valves DD are in communication with the supply-port F, central supply-passage, a?, and passage al, and steam passes through these passages down into the steam-channel O, as represented by the arrows in Figs. l and 2, and while communication between the passages al and d d,

is closed it is open between the corresponding passages a3 and d2 cl2, and the steam is permitted to pass from the channel O through the passages a3, cl2, and a4, and exhaust-port G. When the position of the valves D D is reversed their central passages, d1 d, open communication between the central supply passage, a2, and passage a3, when steam is supplied through channel C and exhausted through channel C, the course ot' the steam through the several passages and ports being just the reverse of that which is traced in the preceding paragraph.

The grooves c (represented in Fig. 3, and designated by the red lines in Fig. 2) are formed in the valves D D to receive and conduct into the exhaust-ports any steam which may work its way into the joints between the valves and valveblock. Hence the steam which would `escape under the various adjustments of the several parts induced by unequal temperature is, by the grooves, directed into the ports, and prevented from making its appearance around the outside of the valve.

2 sacas It will be seen that under this arrangement Having thus described my invention, the thepressure of the steam upon one oi the valves following is what I claim as new and desire to D is connteracted by the pressure upon the secure by Letters Patent:

opposite valve; hence they are strictly bal- The valve-blockAand steam-channels C C a-nced7 there being no friction upon the bear- I of the two balanced slide-valves D D, conings or contiguous faces in consequence of the structed, arranged, and operated substantially action of the steam. as and for the object specified.

It is evident that the number and arrange- JOHN H. WAIT. ment of the passages may be varied Without Witnesses: departing from the essential feature of the in- XV. H. WARE,

vention. A. G. TnoMPsoN. 

